Blind stitcher



Dec. 28, 1954 H, N, JQHNSQN 2,697,992

BLIND STITCHER Filed June 23, 1951 V INVENTOR W ATTORN EYS United StatesPatent lO BLIND STITCHER Harry N. Johnson, New Haven, Conn., assignor toThe Greist Manufacturing Company, New Haven, Conn., a corporation ofConnecticut Application June 23, 1951, Serial No. 233,127

2 Claims. (Cl. 112160) This invention relates to an attachment forsewing machines and more particularly to an attachment for effecting aso-called blind stitch, which attachment may be applied to the ordinarysewing machine designed for household use.

It is desirable that a household sewing machine be equipped foraccomplishing many kinds of work in addition to plain sewing, and inconnection with the hemming of a piece of cloth, it is desirable toprovide an attachment for effecting a so-called blind stitch in sewingthe hem. This is accomplished in the present construction by providingan attachment which will produce a number of stitches in a straight lineand at regular intervals effect an offset stitch or a stitch spaced fromthe line of stitching referred to.

The attachment is provided with a cloth-holding foot pivotally attachedto a frame adapted to be secured to the presser bar of the sewingmachine, and provision is made for shifting this foot pivotally atregular intervals in the operation of the machine to move the clothlaterally to effect an offset stitch. The cloth is then shifted back toits original position so as to continue stitching in a straight lineuntil the lateral shift is again made to produce another offset stitch,it being understood that the offset stitch is produced at spacedintervals along the line of sewing.

Moreover, by the present construction there is provided a device ofsimple character which may be economically manufactured and whichconsists of a relatively small number of parts.

One object of the invention is to provide a new and improved blindstitch attachment for household sewing machines.

Another object of the invention is to provide a blind stitch attachmentfor sewing machines which will be relatively simple in construction andwhich will comprise a relatively small number of movable parts subjectto wear.

Still another object of the invention is to provide a blind stitchattachment for sewing machines comprising elements which will be readilyand accurately manufactured by stamping operations and easily assembledinto the completed mechanism.

A still further object of the invention is to provide a new and improvedblind stitch attachment for sewing machines comprising a frame and acloth-holding foot pivoted to the frame and means for effecting lateraloscillations of the cloth-holding foot about its pivot, which meanscomprises a cam member having spaced lugs thereon to engage a pin orboss upon the pivoted foot member.

To these and other ends the invention consists in the novel features andcombinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a side elevational view of a blind stitch attachment forsewing machines embodying my invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a view similar to Fig. 2 showing the clothholding foot inanother position;

Fig. 4 is a sectional view on line 4-4 of Fig. 3; and

Fig. 5 is a perspective view of the cam member.

`To illustrate a preferred embodiment of my invention I have shown inthe drawing an attachment for effecting blind stitching comprising amain frame of substantially U-shaped form in cross section, this framecomprising a base member and upstanding side members 11 and 12. The basemember 10 is continued forwardly beyond the upstanding side members andprovided upon its for- "ice ward end with an adapter 13 by which it maybe secured to the presser bar of the sewing machine. The base member isalso provided with laterally elongated openings 14 and 15 for a purposeto be hereinafter described.

A pin 16 is secured to the base member and projects downwardlytherefrom, and upon this pin is pivoted a lever 17 having upon itsforward end a downwardly displaced cloth-holding foot 18 provided with alaterally enlarged needle opening 19. A cloth guide 20 is adjustablysecured to the foot 18 by means of the pin 21 and slot 22 so that theguide member may be adjusted relatively to the needle opening.

The rear portion of thislever 17 is offset upwardly from that part whichengages the pin 16, as shown at 23, so that this portion of the leverlies substantially flatly against the underside of the base 10 of theframe. Upon the portion 23 of the lever is provided an opstanding pin orboss 24 which projects upwardly through the opening 14, and at its rearend the portion 23 of the lever is provided with a pin 25 which projectsthrough and is guided by the elongated slot 15 in the base member 10.The pin 24 may be provided with a roller or anti-friction sleeve, ifdesired, to be engaged by the operating cam as will be describedhereinafter.

Rotatably mounted in the upstanding portion 12 of the frame, as shownmore especially in Fig. 4, is a short shaft 27, and secured to thisshaft is a ratchet wheel 28. Loosely mounted upon the shaft 27 is a forkarm 29 upon which is pivotally mounted a pawl 30, the free end of whichis urged into engagement with the teeth of the ratchet wheel 28 by aspring 31. As will be well understood by those skilled in the art, thefork arm is adapted to be secured to the needle bar of the Sewingmachine, and upon reciprocation of the needle bar the oscillations ofthe fork arm will rotate the ratchet wheel and shaft 27 in astep-by-step movement.

The shaft 27 extends through the portion 12 of the frame and upon itsinner end is secured a cam disk 32 by means of the screw 33. As shown inFig. 5, this cam disk may be of substantially circular form and isprovided at diametrically opposite points with cam members or fingers 34and 35. The forward edges of these members may be rounded or beveledoff, as shown at 36 and 37, as these are the active faces of the cammembers.

As shown in Fig. 4, the cam disk 32 is so disposed that its lowerportion lies adjacent the pin 24 which is secured to the pivoted lever17 so that upon rotation of the cam the rounded or beveled edges of thecam fingers 34 and 35 will strike the pin 24 and effect movement of thepin and of the rear end of the lever away from the side frame 12 or tothe left, as shown in Fig. 4. A leaf spring 38 is secured at one end tothe upstanding frame member 11 and the free end of this spring bearsagainst the pin 25 to urge this pin toward the frame member 12 andmaintain the lever 17 in the position shown in Pig. 2 when the pin 24 isnot in contact with one of the cam fingers 34 and 35.

The ratchet wheel 28 may be prevented from rotatingin a reversedirection, during oscillation of the fork arm 29, by means of a holdingpawl in the form of a spring 39 secured to the rear portion of the framemember 12 and projecting forwardly into engagement with the teeth of theratchet wheel. It may also be noted that the pin 25 which is secured tothe portion 23 of the lever 17 is provided with an enlarged head whichlies above the base member 10, while the pin 16 is provided with anenlarged head which lies below the lever 17, thus attaching the lever tothe frame member while permitting pivotal movements thereof.

The operation of the device is as follows. Upon oscillation of the forkarm 29 the ratchet wheel is rotated in a step-by-step movement whichserves to rotate the cam disk 32 in a similar manner. The ratchet wheelis provided with a number of teeth, in this instance 12, and it will beseen, therefore, that as there are two of the cam members 34 and 35, oneof these members will come into engagement with the pin 14 upon everysixth stitch or oscillation of the fork arm 29. When one of these cammembers reaches its lowermost position, as shown in Fig. l adjacent thepin 24, the rounded or beveled surface 36 of the cam member will engagethis pin and move it from the position shown in Fig. 2 at one end of theslot 14 to the position shown in Fig. 3 at the other end of this slot.YThis will move the lever 17 from the position shown in Fig. 2 to thatshown in Fig. 3 and thus move the cloth laterally of the regular line ofstitching. Upon the next descent of the needle bar a laterally offsetstitch will be made, and when the needle bar again ascends, the cammember will be moved out of engagement with the pin 24 and the lever 17will be returned to the position shown in Fig. 2 by the spring 38. Uponcontinued oscillation of the fork arm 29, a series of straight stitcheswill result until the other cam member reaches a position to engage thepin 14. At this time another lateral movement of the lever 17 will beeffected to produce another laterally offset stitch.

It will, of course, be understood that the ratchet wheel may have asmany teeth as desired, and as many of the cam members 34 and 35 may beprovided as desired. With the present arrangement of twelve teeth on theratchet wheel and two cam members, the resulting stitch will consist ofa lateral offset stitch between series of five straight-line or regularstitches. As shown in Fig. 3, it will be noted that the high point ofone of the cam members 34 and 35 will remain in engagement with the pin14 during the descent of the needle bar to make the laterally offsetstitch in order to hold the lever in the position shown in Fig. 3 whilethis stitch is being made. l While I have shown and described apreferred embodiment of my invention, it will be understood that it isnot to be limited to all of the details shown, but is capable ofmodication and variation within the spirit of the invention and withinthe scope of the claims.

What I claim is:

l. In a blind stitch attachment for sewing machines,

a frame comprising a horizontally disposed base member having anelongated opening therein and upstanding side kmembers at each side ofthe base member, a lever pivoted to the base member having acloth-engaging foot at its forward end, said lever having an upwardlyprojecting pin thereon extend-ing through said opening, a horizontallydisposed shaft rotatably mounted on one of said side members, a cam disksecured to said shaft, a pair of spaced diametrically opposite laterallyprojecting cam members on said disk to engage said pin and move thelever about its pivot, means to rotate said shaft in a stepby-stepmovement, said last-named means comprising a fork arm pivoted on theshaft, and a spring secured to the other of said upstanding members andacting horizontally against said pin to urge it toward the disk.

2. In a blind stitch attachment for sewing machines, a substantiallyU-shaped frame comprising a horizontally disposed base member andupstanding side members, one at each edge of the base member, said basemember having an elongated opening therein, a lever pivoted to the basemember at the underside thereof having a cloth-engaging foot at itsforward end, said lever having an upwardly projecting pin thereonextending through said opening, a rotatable cam disk mounted on one ofsaid upstanding side members to rotate on a horizontal axis, said diskhaving a pair of spaced diametrically opposite laterally projecting cammembers thereon to engage said pin, means to rotate said disk, and aspring secured to the other of said upstanding members having a free endengaging said pin to urge it toward said disk.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,067,419 Fefel July 15, 1913 FOREIGN PATENTS Number CountryDate 651,773 Germany Oct. 19, 1937

